Abstract: Construction activities are considered as one of the major air pollutant emissions sources. Specifically, construction equipment produces a large share of the emissions, including carbon oxides, nitrogen oxides, etc. on construction sites. Therefore, it is necessary to monitor and control the operating efficiency of the onsite equipment in order to reduce the amount of its air pollutant emissions. However, the current practices for monitoring and measuring the operating equipment efficiency is heavily dependent on the practitioners’ observations. It is labour-intensive and time-consuming. The main objective of this paper is to present a novel method for automatically monitoring the operating equipment efficiency (OEE) with the fusion of visual and thermal data. Under the method, construction equipment is firstly located and tracked in the visual and thermal data. Based on the locating and tracking results, the equipment value-added activities are identified to determine its valuable operating time. Moreover, the total operating time is determined by checking the duration of the equipment with the running engine. This way, the OEE can be measured as the ratio of the valuable operating time over the total operating time. The method has been tested on the construction site of Poste De Lorimier in Montreal. The test results indicate its effectiveness.